Gabion unit and gabion mesh comprising it

ABSTRACT

A spiral double-twisted structure is provided having an n-th upper steel wire (A n ) and an n-th lower steel wire (B n ) which are paired with each other and rotated in one direction to form a front spiral twisted structure having a plurality of twists. Further, a k-th transverse steel wire (C k ) may be transversely inserted between the n-th upper steel wire (A n )and the n-th lower steel wire (B n )of the front spiral twisted structure. Additionally, the n-th upper steel wire (A n ) and the n-th lower steel wire (B n ) may be rotated in a direction opposite to the one direction after passing over the k-th transversr steel wire (C k ) serving as a centerline, in order to form a rear spiral twisted structure having a plurality of twists.

TECHNICAL FIELD

The present invention relates to a gabion mesh known as a basket or cagefilled with earth or rocks, and more particularly, to a novel gabionunit formed by two longitudinal steel wires and one transverse steelwire, and a gabion mesh having the gabion units consecutively arrangedboth in a right and left direction and in a fore and aft direction.

BACKGROUND ART

Generally, a gabion or gabion mesh is well known as a basket or cagefilled with earth or rocks, and has basic units each of which takes theshape of a rectangle by bending two special zinc-coated steel wires ortwo steel wires with PVC coating further formed thereon, or a hexagon bytwisting two steel wires in such a manner that the steel wires overlapwith each other. Among them, a hexagonal gabion has a firm twistedstructure formed by the two steel wires, and thus, is characterized inthat it has a higher strength over and is stronger than a rectangulargabion. Therefore, the hexagonal gabion is recently preferred to therectangular gabion.

As shown in FIG. 1, the hexagonal gabion is formed in such a manner thattwo steel wires mutually forms a twisted structure, branch off from eachother and then form another identical twisted structure in cooperationwith other adjacent steel wires, and subsequently branch off from eachother again and then form a further identical twisted structure incooperation with the previous adjacent steel wires or other adjacentsteel wires, thereby consecutively repeating such processes.Consequently, such hexagonal basic units are formed both in the rightand left direction and in the fore and aft direction, and mutuallyestablish a consecutive connection relationship among them both in theright and left direction and in the fore and aft direction, resulting ina large gabion in the form of a steel wire mesh. At this time, the twosteel wires can be differentiated into an upper steel wire A guided byan upper slider and a lower steel wire B guided by a lower slider inview of the manufacturing process of the gabion.

Further, FIG. 2 shows an improved version of such a conventionalhexagonal gabion. The improved gabion is formed by inserting anadditional transverse steel wire C into a twisted structure of upper andlower steel wires A and B to halve the size of a hexagon, so that thegabion can be filled with smaller fillers.

Nowadays, such a hexagonal gabion has been used in a variety ofapplications by using the hexagonal mesh structure. This hexagonalgabion is most widely used in the field of engineering and constructionstructures. In this field, for example, a gabion inclination (slope) isformed to protect a cut surface of earth and rocks in a case where thereis a risk of collapse and falling rocks. Alternatively, if constructionof a revetment for a road or cliff is required, a gabion mesh isassembled and filled with gravel or waste rocks (crushed rocks) having asize of 100 to 300 mm to construct a revetment. Further, in a case wherea scour phenomenon has occurred or may occur in a dam or riverconservation structure, a gabion mesh is assembled and filled withfillers to prevent the scour phenomenon in the dam or river conservationstructure.

Particularly, when a revetment or the like is constructed as anengineering and construction structure, fillers for the revetment aregravel or crushed rocks. Thus, underground water permeating from theground can freely flow through spaces among the fillers, therebyachieving natural drain. This eliminates a possibility that waterpressure is produced inside a wall surface of the revetment.Accordingly, there is an advantage in that collapse due to waterpressure can be prevented. Therefore, a gabion revetment is recentlyadmitted as having safety higher than that of other engineering andconstruction structures, and also appraised as having superiorperformance.

Moreover, in the engineering and construction structure using the gabionmesh, ambient earth and sand or the like will be gradually filled intospaces among the empty spaces among the fillers, thereby providing soiland environments in which ambient plants can sprout and grow. Thus,there is an advantage in that the structure using the gabion mesh hassuperior environment-friendliness to similar structures such as concreterevetments or stone reinforcement walls in view of ecology. Therefore,the structure using the gabion mesh is recently widely used as anenvironment-friendly engineering and construction structure in advancedcountries including Europe.

However, even though the gabion mesh has superiorenvironment-friendliness as above, it has several critical problems dueto limitations on its basic configuration as follows.

First, in such a conventional gabion mesh, both longitudinal steel wiresA and B cannot be continuously supplied but one of the steel wires iscut and then supplied. This is because spirally twisted structures ofthe conventional gabion mesh continuously proceed only in one directionand the upper steel wire A should be cut to be relatively short and thensupplied in order to form the twisted structures by consecutivelyspirally rotating the upper steel wire A together with the lower steelwire B in one direction while fixing the lower steel wire B as areference. Nowadays, the upper steel wire A is called “spring steelwire” and is generally used after being cut to be remarkably shorterthan the lower steel wire B.

Further, in manufacturing such a conventional gabion mesh, only anintermittently automated process rather than a fully automated processcan be employed. This is because a conventional method for manufacturingthe gabion mesh employs the shortly cut upper steel wire A, a pluralityof upper steel wires A should be generally supplied until the gabionmesh is completely manufactured using a single lower steel wire B, andrespective tie operations for the upper steel wires A to the lower steelwire B should be manually performed. Thus, there is a disadvantage inthat in manufacturing the conventional gabion mesh, the manufacturingprocess cannot be fully automated.

Furthermore, there is a disadvantage in that skilled workers arerequired for manufacturing the conventional gabion mesh. This isbecause, upon manufacture of the conventional gabion mesh, the uppersteel wires A should be repeatedly coupled to the upper slider duringthe manufacture thereof, and such coupling operations make theautomation of the manufacturing process difficult and require craft ofskilled workers.

In addition, there is a critical disadvantage in that the method formanufacturing the conventional gabion mesh has very low productivity.This is because the manufacturing process of the conventional gabionmesh is performed intermittently and depends on a partially automatedprocess, at least two or three skilled workers are required according tothe size of the gabion mesh, and it takes at least 20 to 30 minuteswhenever the aforementioned coupling process is performed even by suchskilled workers.

Since these problems with the manufacturing process result from theconfiguration itself of the conventional gabion mesh, there areinsoluble limitations on the problems so far as the coupling structureof the gabion mesh or each unit of the gabion mesh is not fundamentallychanged.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view of a conventional hexagonal gabion with a partiallyenlarged view of its basic unit.

FIG. 2 is a view of an improved gabion having longitudinal reinforcementsteel wires with a partially enlarged view of its basic unit.

FIG. 3 is an enlarged view of a spiral double-twisted structure forconstructing a gabion unit of the present invention.

FIG. 4 is a view showing a gabion mesh of the present inventioncomprising a plurality of spiral double-twisted structures of FIG. 3.

DISCLOSURE

Technical Problem

In case of a conventional gabion mesh generally and widely used thesedays, skilled workers are indispensably required in view of itsmanufacturing process and many intermittent coupling processes should beperformed during the manufacturing process. Thus, there is adisadvantage in that productivity thereof is greatly lowered.

Accordingly, an object of the present invention is to provide a spiraldouble-twisted structure, wherein two longitudinal steel wires and onetransverse steel wire are organically coupled to one another in amanufacturing process so that a front spiral twisted structure and arear spiral twisted structure are formed in opposite directions.

Another object of the present invention is to provide a novel gabionunit by manufacturing the spiral double-twisted structure through acontinuous process.

A further object of the present invention is to provide a gabion meshhaving the gabion units consecutively arranged both in a right and leftdirection and in a fore and aft direction.

Technical Solution

The present invention relates to a gabion unit having a novel couplingstructure, and a gabion mesh having the gabion units consecutively andrepeatedly arranged both in the right and left direction and in the foreand aft direction.

The gabion unit of the present invention comprises: 1) one spiraldouble-twisted structure including a k-th transverse steel wire C_(k);2) two spiral double-twisted structures including a (k+1)-th transversesteel wire C_(k+1); and 3) one spiral double-twisted structure includinga (k+2)-th transverse steel wire C_(k+2). In the present invention, thespiral double-twisted structure refers to a structure in which twolongitudinal steel wires are paired with each other to form front andrear spiral twisted structures having opposite twisting directionsbefore and behind one transverse steel wire.

In the present invention, the k-th spiral double-twisted structure isformed in such a manner that: 1-i) an n-th upper steel wire A_(n) and ann-th lower steel wire B_(n) are paired with each other and rotated inone direction to form a front spiral twisted structure, 1-ii) the k-thtransverse steel wire C_(k) is transversely inserted between the n-thupper steel wire A_(n) and the n-th lower steel wire B_(n) of the frontspiral twisted structure, and 1-iii) the n-th upper steel wire A_(n) andthe n-th lower steel wire B_(n) are rotated in a direction opposite tothe one direction after passing over the k-th transverse steel wireC_(k) serving as a centerline, in order to form a rear spiral twistedstructure.

In the present invention, the (k+1)-th spiral double-twisted structureis formed in such a manner that: 2-i) the n-th upper steel wire A_(n) ispaired with an adjacent (n+1)-th lower steel wire B_(n+1) and an(n−1)-th upper steel wire A_(n−1) is paired with the n-th lower steelwire B_(n), and the pairs of steel wires are then rotated in the onedirection to form front spiral twisted structures, respectively, 2-ii)the (k+1)-th transverse steel wire C_(k+1) is transversely insertedbetween the paired two longitudinal steel wires of each of the frontspiral twisted structures, and 2-iii) the paired two longitudinal steelwires are rotated in the direction opposite to the one direction afterpassing over the (k+1)-th transverse steel wire C_(k+1) serving as acenterline, in order to form a rear spiral twisted structure.

In the present invention, the (k+2)-th spiral double-twisted structureis formed in such a manner that: 3-i) the n-th upper steel wire A_(n) ispaired again with the n-th lower steel wire B_(n) and they are thenrotated in the one direction to form a front spiral twisted structure,3-ii) the (k+2)-th transverse steel wire C_(k+2) is transverselyinserted between the paired upper and lower steel wires A_(n) and B_(n)of the front spiral twisted structure, and 3-iii) the paired upper andlower steel wires A_(n) and B_(n) are rotated again in the directionopposite to the one direction after passing over the (k+2)-th transversesteel wire C_(k+2) serving as a centerline, in order to form a rearspiral twisted structure.

The gabion mesh of the present invention takes the shape of a net as awhole by employing the gabion unit as a basic unit and by consecutivelyand repeatedly coupling the gabion units both in the right and leftdirection and in the fore and aft direction through consecutive andrepetitive performance of the series of processes described above.

Herein, the upper and lower steel wires A and B refer to longitudinalsteel wires inserted into upper and lower sliders of a gabion meshmanufacturing apparatus, and the transverse steel wire C refers to atransverse steel wire that is transversely inserted into the twistedstructure formed by the upper and lower steel wires A and B. All thesteel wires refer to steel wires located at relative positions.

Further, n represents herein the relative position relationship amongthe upper and lower steel wires A and B and is a positive integerincluding 0, and k represents the relative position relationship amongthe transverse steel wires C and is a positive integer including 0.

The gabion mesh of the present invention is characterized in that thefront and rear spiral twisted structures of each gabion unit haveopposite twisting directions before and behind the transverse steel wireserving as the centerline.

Advantageous Effects

As described above, the gabion mesh of the present invention has thefront and rear spiral twisted structures formed by organically couplingthe upper and lower steel wires and the transverse steel wire, whereinthe front and rear spiral twisted structures are twisted in oppositedirections before and behind the transverse steel wire serving as thecenterline and also prevented from being untwisted due to the transversesteel wire.

Therefore, the upper and lower steel wires and the transverse steel wirein the gabion mesh of the present invention are firmly coupled to oneanother. Accordingly, there is an advantage in that a firmer meshstructure can be established.

Further, since each double-twisted structure of each gabion unit in thegabion mesh of the present invention has oppositely twisted structures,the upper and lower sliders can return to their initial positions uponmanufacture of each gabion unit and thus do not rotate in only onedirection. Accordingly, it is possible to fully automate the manufactureof the gabion mesh as a whole.

Best Mode

Hereinafter, the present invention will be described in detail withreference to accompanying drawings. However, it will be apparent thatthe accompanying drawings are merely illustrative for the purpose ofmore detailed description of the technical spirit of the presentinvention and the technical spirit of the present invention is notlimited thereto.

FIG. 3 is a partially enlarged view of a spiral double-twisted structure10 _(k) of a gabion unit constituting a gabion mesh of the presentinvention, showing an n-th upper steel wire A_(n) and an n-th lowersteel wire B_(n) in a right and left direction and a k-th transversesteel wire C_(k) in a fore and aft direction.

FIG. 4 shows a gabion mesh 100 in which the spiral double-twistedstructures 10 _(k) for the gabion units are consecutively and repeatedlyconnected to one another both in the right and left direction and in thefore and aft direction. Therefore, FIG. 4 shows that the spiraldouble-twisted structures for the gabion units shown in FIG. 3 areconsecutively and repeatedly connected to one another both in the rightand left direction and in the fore and aft direction.

The gabion unit of the present invention includes the spiraldouble-twisted structure 10 _(k) of the k-th gabion unit. FIG. 3specifically shows the spiral double-twisted structure 10 _(k) of thek-th gabion unit, in which the fundamental technical spirit of thepresent invention is illustrated well.

In the present invention, the spiral double-twisted structure 10 _(k) ofthe k-th gabion unit comprises two spiral twisted structures arrangedwith respect to the k-th transverse steel wire C_(k) and includes then-th upper steel wire A_(n) and the n-th lower steel wire B_(n). Then-th upper and lower steel wires A_(n) and B_(n) are paired with eachother and then rotated in one direction to form a front spiral twistedstructure. At this time, the n-th upper steel wire A_(n) refers to alongitudinal steel wire inserted into an n-th upper slider of a gabionmesh manufacturing apparatus, and the n-th lower steel wire B_(n) refersto a longitudinal steel wire inserted into an n-th lower slider of agabion mesh manufacturing apparatus. They refer to counterpart steelwires located at the same position. Further, the rotation in onedirection herein may be the rotation in a clockwise or counterclockwisedirection. In case of the rotation in one direction, a rotation angle ispreferably integer times of 180° (i.e., π* p, where p is an integerother than 0) when the upper and lower steel wires A_(n) and B_(n) startfrom an upright state with respect to the ground. More preferably, theinteger p is not greater than 10.

In the present invention, the spiral double-twisted structure 10 _(k) ofthe gabion unit includes the k-th transverse steel wire C_(k) that isinserted thereinto transversely with respect to a proceeding directionof the front spiral twisted structure and located between the upper andlower steel wires A_(n) and B_(n). At this time, the transverse wireC_(k) serves to provide a turning point where the upper and lower steelwires A_(n) and B_(n) continuously proceed after the rotation directionthereof is reversed. Therefore, the transverse steel wire C_(k) servesto make the rear spiral twisted structure symmetrical with the frontspiral twisted structure. Contrary to a spiral double-twisted structureof a conventional gabion unit which merely functions as a reinforcementmeans for a gabion mesh, the transverse steel wire C_(k) has a functionof preventing the untwisting of the front and rear spiral twistedstructures in addition to the function as a reinforcement means.

In the present invention, the spiral double-twisted structure 10 _(k) ofthe gabion unit includes the rear spiral twisted structure formed by theupper and lower steel wires A_(n) and B_(n) that have passed over thetransverse steel wire C_(k) serving as a centerline. At this time, therear spiral twisted structure is formed through reverse rotation in adirection opposite to the one direction mentioned above. Therefore, ifthe front spiral twisted structure is formed through clockwise rotation,the rear spiral twisted structure is formed through counterclockwiserotation. If the front spiral twisted structure is formed throughcounterclockwise rotation, the rear spiral twisted structure is formedthrough clockwise rotation. In the state where the rotation direction ofthe rear spiral twisted structure has been completely reversed at thetransverse steel wire, a rotation angle thereof is preferably integertimes of 180° (i.e., π* (−q), where q is an integer other than 0) whenthe upper and lower steel wires A_(n) and B_(n) start from the uprightstate with respect to the ground. More preferably, the integer q is notgreater than 10. More preferably, the number of turns p in the frontspiral twisted structure is identical with the number of turns q in therear spiral twisted structure.

In addition, the gabion unit of the present invention further comprisesspiral double-twisted structures 10 _(k+1) of a (k+1)-th gabion unit(see FIG. 4). At this time, the (k+1)-th gabion unit has two spiraldouble-twisted structures 10 _(k+1) each of which also has adouble-twisted structure. As for the spiral double-twisted structures 10_(k+1) of the (k+1)-th gabion unit, the n-th upper steel wire A_(n)moves to the position of an adjacent (n+1)-th lower steel wire B_(n+1)and is then in a pair, while an (n-1)-th upper steel wire A_(n−1) movesto the position of the n-th lower steel wire B_(n) and is then inanother pair. In such a state, the respective pairs of steel wiresproceed. At this time, the n-th upper steel wire A_(n) is paired withthe (n+1)-th lower steel wire B_(n+1) and they are rotated in onedirection to form a front spiral twisted structure, while the (n−1)-thupper steel wire A_(n−1) is also paired with the n-th lower steel wireB_(n) and they are rotated in one direction to form a front spiraltwisted structure. Of course, the one direction may be a clockwise orcounterclockwise direction. Meanwhile, a rotation angle in the onedirection is preferably integer times of 180° (i.e., π* p, where p is aninteger other than 0) when the upper steel wire A_(n) and the lowersteel wire B_(n+1) start from the upright state with respect to theground and the upper steel wire A_(n−1) and the lower steel wire B_(n)also start from the upright state with respect to the ground. Morepreferably, the integer p is not greater than 10.

Further, the gabion unit of the present invention comprises a (k+1)-thtransverse steel wire C_(k+1) that is inserted transversely with respectto a proceeding direction of the front spiral twisted structures andsimultaneously located between the upper and lower steel wires A_(n) andB_(n+1) and between the upper and lower steel wires A_(n−1) and B_(n).At this time, the transverse wire C_(k+1) serves to provide turningpoints where the upper and lower steel wires A_(n) and B_(n+1) and theupper and lower steel wires A_(n−1) and B_(n) continuously proceed afterthe rotation direction thereof is reversed, respectively. Therefore, thetransverse steel wire C_(k+1) serves to make the rear spiral twistedstructures symmetrical with the front spiral twisted structures.

Further, the gabion unit of the present invention includes the rearspiral twisted structures symmetrical with the front spiral twistedstructures with respect to the transverse steel wire C_(k+1) serving asa centerline. At this time, the rear spiral twisted structure is formedthrough reverse rotation in a direction opposite to the one directionmentioned above. Meanwhile, in the state where the rotation direction ofeach of the rear spiral twisted structures has been completely reversedat the transverse steel wire C_(k+1), a rotation angle thereof ispreferably integer times of 180° (i.e., π* (−q), where q is an integerother than 0) when the upper and lower steel wires A_(n) and B_(n+1)start from the upright state with respect to the ground. Morepreferably, the integer q is not greater than 10. Of course, it is alsotrue even when the upper and lower steel wires A_(n−1) and B_(n) startfrom the upright state with respect to the ground. More preferably, thenumber of turns p in the front spiral twisted structure is identicalwith the number of turns q in the rear spiral twisted structure.

In addition, the gabion unit of the present invention further comprisesa spiral double-twisted structure 10 _(k+2) of a (k+2)-th gabion unit.The spiral double-twisted structure 10 _(k+2) also has a double-twistedstructure. As for the spiral double-twisted structure 10 _(k+2) of the(k+2)-th gabion unit, the n-th upper steel wire A_(n) moves again to theposition of the n-th lower steel wire B_(n) and is paired therewith. Insuch a state, the pair of steel wires proceeds.

The present invention will be described in connection with a mostpreferred embodiment in which the n-th upper steel wire A_(n) movesagain to the position of the n-th lower steel wire B_(n) and thenproceeds. Since this case has the same advantage as a case where upperand lower sliders of the gabion mesh manufacturing apparatus return totheir initial positions and begin to operate again, it can be consideredas the most preferred embodiment. Therefore, the n-th upper steel wireA_(n) and the n-th lower steel wire B_(n) proceed through repetition ofthe same processes as described above except only that a transversesteel wire inserted therebetween is a (k+2)-th transverse steel wireC_(k+2).

The gabion unit of the present invention can be made by consecutivelycoupling the spiral double-twisted structure of the k-th gabion unit,the two spiral double-twisted structures of the (k+1)-th gabion unit,and the spiral double-twisted structure of the (k+2)-th gabion unit toone another.

The gabion mesh 100 of the present invention can be completed byconstructing gabion units through the consecutive and repetitivecoupling of spiral double-twisted structures 10 _(k), 10 _(k+1), 10_(k+2), 10 _(k+) . . . for the series of gabion units of the presentinvention both in the right and left direction and in the fore and aftdirection, and by consecutively and repeatedly coupling the gabion unitsboth in the right and left direction and in the fore and aft direction.

As described above, the gabion unit of the present invention ischaracterized in that the spiral double-twisted structure 10 _(k) as abasic unit of the gabion unit has two spiral twisted structures, i.e.the front and rear spiral twisted structures that are rotated inopposite directions. This is essentially different from the conventionalgabion unit in that both spiral twisted structures of a spiraldouble-twisted structure of the conventional gabion unit are rotated inonly one direction. This enables implementation of full automation of amethod for manufacturing a gabion mesh, which was impossible inprinciple in a conventional manufacturing method.

Further, although the gabion mesh 100 of the present invention has thefront and rear spiral twisted structures that are formed through therotations in opposite directions, the twisted structures thereof are notuntwisted due to the transverse steel wire C_(k). Therefore, thetransverse steel wire C_(k) provides a foundation for forming the frontand rear spiral twisted structures in the manufacturing process, andsimultaneously performs the functions of maintaining the existing statesof the front and rear spiral twisted structures and preventing theuntwisting thereof in the spiral double-twisted structure 10 _(k) of thecompleted gabion unit.

Although the gabion unit and the gabion mesh using the same according tothe present invention have been specifically described above, thedescription has been made only in connection with the most preferredembodiment of the present invention. The present invention is notlimited thereto, and the scope of the present invention is defined bythe appended claims. Further, it will be apparent that those skilled inthe art can make various modifications and changes upon reading of thedescription without departing from the scope of the present invention.

1. A spiral double-twisted structure for a gabion unit of a gabion mesh,comprising: an n-th upper steel wire (A_(n)) and an n-th lower steelwire (B_(n)) which are paired with each other and rotated in onedirection to form a front spiral twisted structure having a plurality oftwists, a k-th transverse steel wire (C_(k)) which is transverselyinserted between the n-th upper steel wire (A_(n)) and the n-th lowersteel wire (B_(n)) of the front spiral twisted structure, and the n-thupper steel wire (A_(n)) and the n-th lower steel wire (B_(n)) which arerotated in a direction opposite to the one direction after passing overthe k-th transverse steel wire (C_(k)) serving as a centerline, in orderto form a rear spiral twisted structure having a plurality of twists,where k represents the relative positional relationship among transversesteel wires and is a positive integer including 0, and n represents therelative positional relationship among the upper and lower steel wiresand is a positive integer including
 0. 2. A gabion unit including twolongitudinal steel wires and one transverse steel wire, comprising: ak-th spiral double-twisted structure including a k-th transverse steelwire (C_(k)), the k-th spiral double-twisted structure being configuredsuch that an n-upper steel wire (A_(n)) and an n-th lower steel wire(B_(n)) are paired with each other and rotated in one direction to forma front spiral twisted structure having a plurality of twists, the k-thtransverse steel wire (C_(k)) is transversely inserted between the n-thupper steel wire (A_(n)) and the n-th lower steel wire (B_(n)) of thefront spiral twisted structure, and the n-th upper steel wire (A_(n))and the n-th lower steel wire (B_(n)) are rotated in a directionopposite to the one direction after passing over the k-th transversesteel wire (C_(k)) serving as a centerline, in order to form a rearspiral twisted structure having a plurality of twists, where krepresents the relative positional relationship among the transversesteel wires and is a positive integer including 0, and n represents therelative positional relationship among the upper and lower steel wiresand is a positive integer including 0; two (k+1)-th spiraldouble-twisted structures including a (k+1)-th transverse steel wire(C_(k+1)); and one (k+2)-th spiral double-twisted structure including a(k+2)-th transverse steel wire (C_(k+2)), where k represents therelative positional relationship among the transverse steel wires and isa positive integer including
 0. 3. The gabion unit as claimed in claim2, wherein the (k+1)-th spiral double-twisted structure is formed suchthat: the n-th upper steel wire (A_(n)) is paired with an adjacent(n+1)-th lower steel wire (B_(n+1)) and an (n−1)-th upper steel wire(A_(n −1)) is paired with the n-th lower steel wire (B_(n)), and thepairs of steel wires are then rotated in the one direction to form frontspiral twisted structures, respectively, the (k+1)-th transverse steelwire (C_(k+1)) is transversely inserted between the paired twolongitudinal steel wires of each of the front spiral twisted structures,and the paired two longitudinal steel wires are rotated in the directionopposite to the one direction after passing over the (k+1 )-thtransverse steel wire (C_(k+1)) serving as a centerline, in order toform a rear spiral twisted structure, where k represents the relativepositional relationship among the transverse steel wires and is apositive integer including 0, and n represents the relative positionalrelationship among the upper and lower steel wires and is a positiveinteger including
 0. 4. The gabion unit as claimed in claim 1, whereinthe (k+2)-th spiral double-twisted structure is formed such that: then-th upper steel wire (A_(n)) is paired again with the n-th lower steelwire (B_(n)) and they are then rotated in the one direction to form afront spiral twisted structure, the (k+2)-th transverse steel wire(C_(k+2)) is transversely inserted between the paired upper and lowersteel wires (A_(n), B_(n)) of the front spiral twisted structure, andthe paired upper and lower steel wires (A_(n), B_(n)) are rotated againin the direction opposite to the one direction after passing over the(k+2)-th transverse steel wire (C_(k+2)) serving as a centerline, inorder to form a rear spiral twisted structure, where k represents therelative positional relationship among the transverse steel wires and isa positive integer including 0, and n represents the relative positionalrelationship among the upper and lower steel wires and is a positiveinteger including
 0. 5. A gabion mesh, comprising: gabion unitsaccording to claim 2 consecutively and repeatedly coupled to one anotherboth in a right and left direction and in a fore and aft direction.
 6. Agabion mesh, comprising: gabion units according to claim 3 consecutivelyand repeatedly coupled to one another both in a right and left directionand in a fore and aft direction.
 7. A gabion mesh, comprising: gabionunits according to claim 4 consecutively and repeatedly coupled to oneanother both in a right and left direction and in a fore and aftdirection.
 8. The spiral double-twisted structure according to claim 1,wherein the spiral double-twisted structure is bisected by the k-thtransverse steel wire (C_(k)).
 9. The gabion unit according to claim 2,wherein the k-th spiral double-twisted structure is bisected by the(k+1)-th transverse steel wire (C_(k+1)).